307 
adcauline. portion of the 'diaphragms. "Each branchlet is divided 
into 3—6 internodes, each of which bears 3—10 hydrothecae, 
the number of the latter in each internode. decreasing as a rule 
towards the distal end. In the stem as also in the axes of the 
composite branches the hydrothecae are arranged into two well- 
divided longitudinal series, but while the internodes of the proximal 
portion of the stem bear 3 hydrothecae those of the distal portion 
are only provided each with a single one, placed at the origin of 
the branch. The axial internodes of the composite branches bear 
3—6 hydrothecae. 
The gonothecae, of which I have seen a few borne by the 
stems and by the proximal part of a number of branchlets, are 
elongate, smooth, from the middle decreasing in thickness towards 
both ends, the distal of which is somewhat tubiform. 
Georgia from off the mouth of the river Savannah. Depth 4 fathoms. 
I have examined two incomplete colonies sent me from the 
Zoological Museum of Upsala!). 
Allman's short and incomplete description as also his ac- 
companying figures agree very well with the present species, and 
the only disagreement is that according to Allman "the hydrothecae 
are adnate for nearly their whole length”, but this difference "may 
very well be the result of variation. The author especially points 
out that "Thujaria plumulifera has a good deal of the habit of 
Hydrallmania falcata.” "On the other side Nutting's species, of 
which he has sent me some fragments, is not identical with All- 
man's. It is a Sertularia, the hydrothecae of which are provided 
with a rather long, free distal portion and have the adcauline 
sinus feebly divided into two lateral halves. In opposition to what 
is the case in H. plumulifera there is no spiral arrangement of 
the branches, and the internodes which are not sharply divided 
from each other and each of which bears a branch, are of me 
unequal length, each bearing 3—15 hydrothecae, 
1) I have later received a fragment of the original specimen from ka 
Museum of Comp. Zoology, Cambridge, 
20" 
